Helonic is an AI construction drawing analysis platform for teams researching architectural plan symbols during drawing review. Complete reference for common symbols found on architectural floor plans, elevations, and details
Symbols can vary between firms and projects. Always refer to the project's legend (usually on Sheet A-001 or in the general notes) for project-specific symbols and abbreviations.
Wall symbols on an architectural plan distinguish new walls, existing walls to remain, demolition, fire-rated assemblies, and non-structural partitions by line weight and hatch.
| Symbol | Meaning | Notes |
|---|---|---|
| ━━━━ | Solid wall (new construction) | Usually thicker line weight |
| ┅┅┅┅ | Existing wall to remain | Dashed or lighter weight |
| ╳╳╳╳ | Wall to be demolished | Crossed out or hatched |
| ▓▓▓▓ | Fire-rated wall | Often hatched or noted with rating |
| ░░░░ | Partition (non-structural) | Lighter than structural walls |
Door symbols show swing type and direction: single-swing, double-swing, sliding, pocket, revolving, and bi-fold, with an arc or arrow for the path of travel.
| Symbol | Meaning | Notes |
|---|---|---|
| ┐╲ | Single swing door | Arc shows swing direction |
| ╱┬╲ | Double swing door | Two arcs from center |
| ⟷ | Sliding door | Arrow shows slide direction |
| ◠ | Pocket door | Slides into wall pocket |
| ⟲ | Revolving door | Circle with partitions |
| ◠─ | Bi-fold door | Accordion pattern |
Window symbols mark fixed, operable, casement, and awning or hopper units inside the wall, with a cross, diamond, or triangle showing how the sash moves.
| Symbol | Meaning | Notes |
|---|---|---|
| ═══ | Fixed window | Parallel lines in wall |
| ═╪═ | Operable window | Cross indicates moveable sash |
| ═◇═ | Casement window | Diamond shows hinge side |
| ═△═ | Awning/hopper window | Triangle shows swing direction |
Stair and ramp symbols mark up and down direction, the break line where the run continues, and ramps with a slope indication.
| Symbol | Meaning | Notes |
|---|---|---|
| ▲ UP | Stairs going up | Arrow indicates direction of travel |
| ▼ DN | Stairs going down | DN or DOWN noted |
| ─//─ | Break line | Indicates stair continues |
| ◢ | Ramp | With slope indication |
Reference marks point you to another sheet: section cuts, elevation tags, detail callouts, room numbers, and door tags that carry a number and sheet reference.
| Symbol | Meaning | Notes |
|---|---|---|
| ① | Section cut | Number refers to sheet/detail |
| ▲ | Section direction | Arrow shows viewing direction |
| ◐ | Elevation tag | Circle with detail number |
| ⬡ | Detail callout | Hexagon or circle with number |
| ○ | Room number/tag | Circle or oval with room ID |
| ⬭ | Door tag | Often includes door number |
Level and dimension marks locate grids, spot elevations, datum levels, survey benchmarks, and dimension strings so you can read height and distance off the plan.
| Symbol | Meaning | Notes |
|---|---|---|
| ⊕ | Column grid intersection | Grid lines labeled A, B, 1, 2, etc. |
| ⊥ | Spot elevation | Shows elevation at a point |
| ━⊥━ | Level datum | Horizontal reference level |
| ⊙ | Benchmark | Survey reference point |
| ├──┤ | Dimension string | Shows measurement between points |
Fixture and equipment symbols mark toilets, lavatories, tubs, showers, and appliances as simple shapes that the plumbing or kitchen schedule then specifies.
| Symbol | Meaning | Notes |
|---|---|---|
| ◻ | Toilet | Oval or rectangle shape |
| ▭ | Sink/lavatory | Bowl shape with drain |
| □ | Tub | Rectangle, sometimes with drain |
| ⌓ | Shower | Square with drain indication |
| ▣ | Appliance | Rectangle with cross or label |
Material hatching patterns distinguish earth, concrete, masonry, wood, insulation, and other assemblies in section so reviewers can read the wall or floor build-up.
Section and detail tags use a two-part callout, detail number over sheet number, so a mark like 3/A-501 means detail 3 on sheet A-501.
Related references for architectural drawing interpretation.